Challenges presented

• Trench excavation in open waters during winter months
• Trench excavation between two possible anomalies

Irish Sea Contractors (ISC) were assigned to construct the Dunmore East Storm Outfall located at the Strand. ISC appointed Foyle & Marine Dredging as the dredging contractor to dredge the outfall pipeline trench and provide marine plant support throughout installation.

The trench excavation and 630MM HDPE pipeline installation was organised around 5 days a weather opportunity. For complete accuracy the outfall alignment, depth, falls and the two possible anomaly locations were uploaded to the Spud leg dredger Aoibheanne’s Prolec Pcx dredge system prior to commencement.

On final installation and survey, the outfall pipe was backfilled with existing material prior to marker buoys being installed.